Personalized Rawr I'm One Dinosaur Toddler Dress. Rawr! I'm One! A cute T Rex dinosaur holding a megaphone and wearing a birthday party hat roars to let everyone know its birthday is here. Cute gift for your one year old's 1st birthday. Your little one will be adorable and comfortable in this 100% combed ringspun cotton 1x1 baby rib dress!